Amtlib.dll is a dynamic link library (DLL) file that is used by Adobe software, including Photoshop CS5, to manage licensing and activation. The file is responsible for verifying the software's license and ensuring that it is properly activated. Without a valid license, the software will not function.

: Modifying system or application files can lead to software instability, security risks, and legal consequences.

The query specifies "64bit." Software compiled for 64-bit architecture has a different internal structure than 32-bit software. A 32-bit DLL cannot be used to crack a 64-bit application. Therefore, the cracked file must be specifically compiled to match the 64-bit memory addressing of the host operating system and the Photoshop CS5 executable.